1. Field of the Invention
The present invention relates to a vehicle dynamics control system (vehicle motion control system) that enables a plurality of vehicle behavior control units to act properly according to the conditions of a road on which a vehicle is driven, and a vehicle having the vehicle dynamics control system. Herein, the plurality of the vehicle behavior control units include a front-rear traction distribution control unit for for wheel drive vehicles, an anti-lock brake control unit, a traction control unit, and a braking power control unit which are mounted on the vehicle.
2. Description of the Related Art
In recent years, various vehicle behavior control units including a front-rear traction distribution control unit for four wheel drive vehicles, an anti-lock brake control unit, a traction control unit, and a braking power control unit have been mounted in a vehicle.
The vehicle behavior control units are each properly controlled based on driving conditions of the vehicle or an environment in which the vehicle is driven. For example, Japanese Unexamined Patent Publication No. 9-290655 has disclosed an art of the front-rear traction distribution control unit for four wheel drive vehicles. The front-rear traction distribution control unit timely and adequately detects the situation of a road to be attained at a time instant, at which the vehicle is actually driven on the road, based on the driving conditions of a preceding vehicle. The front-rear traction distribution control unit then controls a torque distribution rate, at which a driving force is distributed to front wheels and rear wheels, according to the detected situation of the road.
Moreover, Japanese Unexamined Patent Application Publication No. 2000-127931 has disclosed an art of calculating and correcting a magnitude of operation. Specifically, an actual kinetic state of a vehicle is compared with a reference kinetic state in order to calculate the magnitude of operation to be performed to control the behavior of the vehicle. A braking force and a driving force for the vehicle are controlled based on the magnitude of operation. The direction of the road estimated based on information provided by a navigation system is compared with a direction in which the vehicle is driven forwards and which is estimated based on the kinetic state of the vehicle in order to correct the magnitude of operation.
However, although the foregoing vehicle behavior control units each act properly, when they are mounted in a vehicle, they may act all together so as to keep the driving condition of the vehicle at an optimal state, and eventually excessively control the vehicle.
Moreover, when the plurality of the vehicle behavior control units are mounted in the vehicle, the magnitudes of controls by which the vehicle behavior control units act and the sensibilities of the vehicle behavior control units may be modified or adjusted. However, the timing is most important to control the behavior of the vehicle. A time-varying change in the driving condition of the vehicle must be reflected on the magnitudes of the controls, by which the vehicle behavior control units act, so that the vehicle behavior control units can respond to the time-varying change as quickly as possible.
Accordingly, an object of the present invention is to provide a vehicle dynamics control system and a vehicle having the vehicle dynamics control system, wherein the vehicle dynamics control system enables a plurality of vehicle behavior control units mounted in a vehicle to act efficiently while responding quickly to road conditions and shape of a road on which the vehicle is driven, and wherein the vehicle behavior control units are well-balanced with one another. Consequently, the vehicle dynamics control system enables the vehicle behavior control units to optimally control the motion of the vehicle.
For accomplishing the object, according to the present invention, there is provided a vehicle dynamics control system comprising road information recognizing means, vehicle behavior control means, and variable control means. The road information recognizing means detects and recognizes the situation of the road. The vehicle behavior control means controls a behavior of a vehicle. The variable control means can vary depending on the situation of the road and the shape thereof at least either the magnitudes of control or the sensibility of the vehicle behavior control means in intervening in control actions.
The above and other objects, features and advantages of the invention will be become more clearly understood from the following description when referring to the accompanying drawings.